AV Evasion Methodology
Currently, AVs use different methods for checking if a file is malicious or not, static detection, dynamic analysis, and for the more advanced EDRs, behavioural analysis.Static detection
Static detection is achieved by flagging known malicious strings or arrays of bytes in a binary or script, and also extracting information from the file itself (e.g. file description, company name, digital signatures, icon, checksum, etc.). This means that using known public tools may get you caught more easily, as they've probably been analyzed and flagged as malicious. There are a couple of ways of getting around this sort of detection:- Encryption
- Obfuscation
- Custom tooling